Japanese Patent Laid-Open No. 11-287139 discloses a variable valve apparatus that varies valve-opening characteristics of an intake valve or an exhaust valve. The aforementioned variable valve apparatus includes a plurality of rocker arms that are driven by a plurality of cams that have different lifts, and a switching mechanism that switches between a state that connects the rocker arms through a pin (connecting piston) and a state that releases the connection.
Japanese Utility Model Laid-Open No. 61-48905 discloses a valve mechanism in which a hydraulic lash adjuster is arranged in a rocker arm, and the hydraulic lash adjuster contacts against a valve stem. According to this valve mechanism, an oil supply path for supplying oil to the hydraulic lash adjuster is formed inside the rocker arm. Oil in an oil path formed within a rocker shaft that supports the rocker arm is supplied to the hydraulic lash adjuster through the aforementioned oil supply path.
Patent Document 1: Japanese Patent Laid-Open No. 11-287139
Patent Document 2: Japanese Utility Model Laid-Open No. 61-48905
Patent Document 3: Japanese Patent Laid-Open No. 2006-57535